Research Of Structural Reliability Based On Recursive Stochastic Finite Element Method

The purpose of these research works is to develop a theoretical method for the safety research of structure after the literature' method compare analysis, and this method which is called based on the recursion stochastic finite element method (RSFEM) of the structure reliable target computational method can enhance the computation precision of the reliable target. Hence exploring research works on the follow aspects have been done around the purpose.1. Induce and summarize the research condition of reliability problems involving random variables both at home and abroad;introduce concretely stochastic finite element method and its various algorithms;stress random space expression and perturbation stochastic finite element method on the basis of minor parameter perturbation, deterministic analysis and recursive equations.2. The title show that compared with perturbation stochastic finite elements method based on Taylor expansion, the results obtained utilizing RSFEM are found to be more close to those of Monte-Carlo simulation in relatively large range of random fluctuation and even if only taking the first four items of nonorthogonal polynomials expansion, effectiveness of RSFEM is still well.3. Elaborated the general method of structure margin of safety analysis, then emphasis introduced a method of checking calculation "(the LC method)". Which method may carry on the more precisely approximate calculation result to the reliability, and using the iteration computational method, obtaining the design value of "the checking calculation spot" which satisfies the limiting condition equation, which is advantage for the standard value computation sub-item coefficient which produces according to the standard, and favors designer to use the habitually multi-coefficients design expression.4. Proposed one newly method which based on the RSFEM stochastic structure margin of safety target computational method. In this method, according the example of the cantilever beam and 5 cross girder constructions computation, and comparing with the perturbation stochastic finite element method, we may obtain this value method to be able to carry on a more precise expression to the stochastic structuremargin of safety target. Its result also unusual tally with the MC analogue result, which has proven that based on the RSFEM stochastic structure margin of safety target computational method is rationality and the validity.